Mechanism of Turn-To-Turn Protection Maloperation and Anti-Maloperation Measure for HVSR

When a high-voltage shunt reactor (HVSR) is applied in a long transmission line system equipped with series compensation devices, the non-periodic components generated during fault recovery may cause maloperation of the HVSR turn-to-turn Protection Maloperation, compromising system stability and reliability. This paper investigates a busbar HVSR turn-toturn Protection Maloperation maloperation case encountered in engineering practice, studying the generation mechanism of lowfrequency current components during fault recovery. From the perspective of protection criteria, it analyzes the impact of lowfrequency components on HVSR turn-to-turn Protection Maloperation. Building upon existing protection criteria, the proposed anti-maloperation measure incorporates a Butterworth filter to process sampled signals before calculating the zerosequence power frequency components for interturn short-circuit fault discrimination. This effectively prevents protection maloperation induced by low-frequency components. The mechanism of HVSR turn-to-turn Protection Maloperation maloperation and the effectiveness of the proposed solution are validated through simulation models constructed on the PSCAD/EMTDC platform, demonstrating the technical correctness and operational effectiveness of the methodology.